In the Garden:Lower South
February, 2004
Regional Report

Flowers like chamomile attract beneficial insects, such as this tiny hover or syrphid fly, whose larvae feed on aphids and other pests.

Gardening for the Bugs

You may have heard about gardens that attract birds or perhaps wildlife in general. Then there are butterfly gardens, a popular rage these days. What about gardens that attract bugs? Well you may think your garden does that already, but I'm not talking about pests here. I mean a garden that attracts beneficial insects.

There are a host of insects, mites, and other creepy crawlies that are our allies in gardening, attacking pests and helping to keep their populations from getting out of control. The very fact that you don't have to spray almost everything you grow every year for a plethora of pests is a tribute to the work of these silent sentries.

Beneficial insects are part of the natural ecosystem. Our gardening designs and practices either discourage or encourage them to visit and set up housekeeping. You can design a garden that attracts them and encourages them to stick around so when a pest shows up, it stands about the same chance as a June bug in a pen full of chickens!

Here are four simple steps to attracting beneficial insects to our gardens and to make sure they stay around:

Include Water
Provide an accessible source of water. A birdbath with some stones that stick up out of the water for perching, or a periodic sprinkling of plants works great. Even drip irrigation is a useful source of water for beneficial insects.

Favorite Plants
Plant flowers to provide nectar and pollen for adult beneficials, such as syrphid flies and parasitic wasps, to feed upon. Among the better pollen food sources are plants that have umbrella-shaped flowers, such as dill, yarrow, tansy, and fennel. Other plants to include are those with small daisy-like flowers, such as chamomile and feverfew; and blooming herbs, such as thyme, oregano, and rosemary.

If you plant root vegetables (carrots, radishes, turnips), leave a few to go to seed because their blooms are favored by some beneficial insects. In my garden I have also noticed beneficials on the blooms of chives and cilantro (coriander).

Leave Some Pests for Food
Allow some pests to remain as a food source for beneficial larvae (and some adults too). Zero pest populations are not sustainable and will leave beneficials with no reason to stay in your garden area. Lady beetles are our friends but they are not philanthropic! They lay eggs on plants that have some pests so their babies can have food; no pests, they will move on. Mexican (or tropical) milkweed and gaura are good plants to use for supporting a few aphids so beneficials will stick around. The aphid species that these plants attract are not pests of most of our garden and landscape plants.

Pesticides Kill Beneficials Too
Avoid pesticides that can damage beneficial insects. This includes both organic and synthetic products. When a situation warrants a spray, select a product with a narrow spectrum of control (like Bacillus thuringiensis for caterpillars) to avoid killing other insects. Choose one that breaks down fast. Direct it only at the plants with the pest problem.